The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor implicitly admitted as prior art against the present disclosure.
A rewriteable disc is manufactured to have a glossy rewriteable layer. To write to a rewriteable disc, a laser beam with relatively high power is used to quickly melt portions of the disc's rewriteable layer, thereby causing those portions to lose their glossy state and become amorphous. The differences in reflectivity between glossy and amorphous portions of the disc are detected when reading from the optical disc. To erase a rewriteable disc, a laser beam with a relatively low power used to slowly melt the rewriteable layer, which causes the rewriteable layer to assume its crystallized or glossy state upon cooling.
Optical drive writing performance often varies due to factors such as manufacturing differences between various optical drives, differences between various recordable media (such as type of disc, brand of disc), and differences in disc speeds. Environmental conditions such as temperature can also have an impact on optical drive writing performance. Optical media manufacturers often include “address in pre-goove” (ADIP) information that provides write strategy parameters (such as write power and pulse shape) to the optical drive. But drive developers often determine that an alternative write strategy works better for their particular drives, and they therefore program alternative write parameters into the drive firmware to override the ADIP information.